TOPLINE

Children undergoing strabismus surgery who received moderate-to-deep neuromuscular blockade (NMB) had a reduced incidence of oculocardiac reflex compared with children who received minimal-to-shallow NMB, with a shorter duration of oculocardiac reflex observed. 

METHODOLOGY

• Researchers conducted a prospective randomized controlled trial in Seoul, Republic of Korea, including 201 pediatric patients aged 3-18 years with American Society of Anesthesiologists physical status I-III scheduled for elective strabismus surgery under general anesthesia.
• Participants were randomly assigned to receive either moderate-to-deep NMB (n = 99) with rocuronium 1.0 mg/kg or minimal-to-shallow NMB (n = 102) with rocuronium 0.3 mg/kg, with NMB monitored using electromyography and reversed with sugammadex that targeted a train-of-four ratio greater than 0.9.
• The primary outcome was the incidence of oculocardiac reflex grade of 2 or greater during surgery, which was defined as at least a 20% decrease in the heart rate from baseline.
• The secondary outcomes were the incidence of oculocardiac reflex grade of 1 or higher, grade 3 or higher, and grade 4 or higher. The requirement for rescue atropine administration, incidence of postoperative nausea and vomiting in the post-anesthesia care unit, and other outcomes were also evaluated.

TAKEAWAY

• The incidence of oculocardiac reflex grade 2 or higher was significantly lower in the moderate-to-deep NMB group than in the minimal-to-shallow NMB group (30.3% vs 53.9%; odds ratio [OR], 0.37; P = .001). The moderate-to-deep NMB group remained independently associated with a significantly reduced risk for oculocardiac reflex grade of 2 or more in an adjusted analysis.
• Severe oculocardiac reflex (grade ≥ 3) occurred less frequently in the moderate-to-deep NMB group than in the minimal-to-shallow NMB group (18.2% vs 35.3%; OR, 0.41; P = .007), with no significant difference noted in the incidence of oculocardiac reflex grade 1 or more between groups.
• Among patients experiencing oculocardiac reflex events, the maximum heart rate reduction was greater in the minimal-to-shallow NMB group vs moderate-to-deep NMB group (34.3% vs 27.0%; median difference, 7.5%; P = .003) and the duration of the oculocardiac reflex was also longer (46 vs 37 seconds; median difference, 13 seconds; P = .024).

IN PRACTICE

The results “suggest that moderate-to-deep neuromuscular blockade can play a role in preventing severe OCR [oculocardiac reflex] and reducing its severity. Therefore, neuromuscular blockade may serve as a titratable, dose-dependent strategy for OCR prevention and recovery during pediatric strabismus surgery,” the researchers reported.

SOURCE

This study was led by Jung-Bin Park, MD, PhD, of the Department of Anesthesiology and Pain Medicine in the Seoul National University Hospital at Seoul National University College of Medicine in Seoul, South Korea. It was published online on July 15 in Anesthesiology.

LIMITATIONS

This study was conducted at a single tertiary center and included relatively healthy children, which might limit the applicability of the findings. NMB was assessed using two predefined depth groups rather than across a range of blockade levels, which may affect the determination of a graded dose-response relationship between NMB depth and oculocardiac reflex outcomes. Prophylactic anticholinergics were not used in this study.

DISCLOSURES

Hallim Pharmaceutical Co., Ltd., Republic of Korea, provided support for the study. The authors reported no financial conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.